1. Field of the Invention
The present invention relates to a method and apparatus for controlling the power consumption of terminal in a network, and more particularly, to a method and apparatus for driving a remote terminal.
2. Description of Related Art
The energy star program of the US government, announced in 1963, limits the power consumption of a personal computer when not in use, and the US government prohibits the sale of any product not manufactured according to this standard. PC manufacturers have developed products to follow this standard. However, with the development of networks, which connect PCs to each other, a need has arisen for network administrators to update software through the network or carry out data back up while users are away from their PCs. To perform such operations the PC must be in a normal state, and to achieve this a so-called “magic packet” that can wake up a remote terminal from a sleeping state has been proposed.
FIG. 1 is a diagram illustrating the format of a conventional magic packet.
Referring to FIG. 1, the magic packet includes an Ethernet header, a synchronization field, a magic packet discriminating field, and other fields. The magic packet is an Ethernet frame and follows the Ethernet standard.
A person who wants access to a remote terminal creates a magic packet as shown in FIG. 1 and transmits the magic packet to the remote terminal. The remote terminal receives the magic packet and compares a destination address, which is recorded on a destination address field of the Ethernet header of the received magic packet, with its own address. If the addresses match, the magic packet is processed according to a magic packet processing method.
To be more specific, first of all it is checked whether the value recorded on the synchronization field is FF repeated six times. If this condition is satisfied, it is checked whether the value recorded on the magic packet discriminating field is the media access control (MAC) address of a remote terminal repeated sixteen times. If this condition is also satisfied, then a wake-up signal is transmitted to the main system that is in a sleeping state. The main system, which receives the wake-up signal, wakes up by booting up.
However, since an arbitrary user can wake-up a sleeping remote terminal with a magic packet, without the user of the remote terminal being aware, a malicious user can retrieve information stored in the remote terminal or carry out other damaging operations.
In addition, since the magic packet is processed in the link layer using only the MAC address, services provided by higher layers such as the network layer cannot be used. For example, routing services, provided by a router that configures the transmission pathway of a packet on the basis of the IP address, cannot be used.